


Trust No One

by Szeherezada



Category: Haikyuu!!
Genre: Haikyuu Secret Santa, Hogwarts AU, M/M, Prank War, i'm really sorry i'm so late, it's comedy despite the title okay
Language: English
Status: Completed
Published: 2018-01-27
Updated: 2018-01-27
Packaged: 2019-03-10 05:39:15
Rating: General Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 4,366
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/13495992
Author URL: https://archiveofourown.org/users/Szeherezada/pseuds/Szeherezada
Summary: A few seconds later, with the only warning being a happy, vibrant, but short melody of bells, reminiscent of the last notes of a music box, Oikawa and Kuroo’s cups—or rather the content of their cups—shot up like water from a fountain, drenching them both along with Matsukawa.“It means war!”“Exactly!”“I’m in!”Or: apparently the teachers had fun observing those dumbasses, too, because no one got suspended.





	Trust No One

**Author's Note:**

  * A translation of [Nie Ufaj Nikomu](https://archiveofourown.org/works/13496164) by [Szeherezada](https://archiveofourown.org/users/Szeherezada/pseuds/Szeherezada). 



> It's the gift for [Bo's Saeko](https://bo-saeko.tumblr.com/) for [Haikyuu!! Secret Santa 2017](https://haikyuusecretsanta.tumblr.com/). Once again - I'm really sorry it took me so long, real life caught up with me. I hope you'll like it and won't think the wait wasn't worth it :'D  
> Fic originally in Polish (I don't feel confident enough to write in English, so I write in my native language and then translate the fic later). Beta: [cara1317](http://archiveofourown.org/users/cara1317/pseuds/cara1317) (thank you! <3)

Iwaizumi should have been alarmed when he saw Matsukawa and Hanamaki exchange cunning smirks during History of Magic, but he didn’t have any desire nor energy to try to find out what his friends were plotting. The quidditch match against the Slytherins was getting closer and closer, and Iwaizumi, as Gryffindor’s team captain, needed to focus on coming up with good tactics—tactics that would ensure they would win. Iwaizumi normally wouldn’t be as keen on winning (they were actually ahead of the Slytherins in House Points), but he had personal reasons: Oikawa was leading the opposite team. Iwaizumi loved his boyfriend with all his heart, but there was no chance this idiot would win... again. Iwaizumi would rather be kissed by a Dementor. 

A paper plane landed next to him on the table with barely audible plop. Hanamaki picked it up. Carefully, he flicked his wand and the paper spread out, rustling quietly. Iwaizumi leaned toward Hanamaki’s direction, curious as to what the troublesome duo was planning, but Hanamaki covered Matsukawa’s sloppily scribbled answer with his hand. He gave Iwaizumi an indulgent half-smile and muttered, “I’m sorry, man. That’s top secret.”

Iwaizumi rolled his eyes playfully, but a little anxious. Ever since Oikawa and him had met Hanamaki and Matsukawa during their first year, on the Hogwarts Express, the four of them had established a close bond right away. Even though they joined different houses-Iwaizumi and Hanamaki in Gryffindor, Oikawa in Slytherin, and Matsukawa in Hufflepuff—their bond wasn’t weakened. It was the opposite, actually: over the years, their friendship grew stronger and stronger. And now, in their seventh year at Hogwarts, it was rather uncommon for his friends to hide something from him. The fact they didn’t want to share their plans meant trouble. It was better to stay careful. 

Iwaizumi watched Hanamaki from the corner of his eye. His friend was hurriedly and eagerly writing a long and apparently really detailed answer. He would have looked like a very attentive student for their teacher if his normal, problematic behaviour didn’t tell otherwise. Finishing his note, Hanamaki flicked his wand and refolded the parchment into a plane, the little model ready to fly once their teacher turned his attention to the other side of the room, occupied by Hufflepuffs.

The lesson—the last one for today—ended not long after. After lunch in the Great Hall, it was time for Gryffindor’s quidditch practice. Hanamaki didn’t act suspiciously though, like Iwaizumi expected him to do, and Iwaizumi assumed, with a relief embracing him with soothing feeling of peace, that he wasn’t on the viewfinder. Unfortunately, his suppositions would be confirmed that evening, during the dinner.

After abundant, delicious dishes, Hanamaki left the Gryffindors’ table, marched past the Ravenclaw table to the Hufflepuffs’, where Matsukawa joined him. The two halted at the Slytherin table. More precisely, they stopped next to Oikawa and Kuroo, who were in the middle of talking about something, probably their tactics for the match against Gryffindor. They stopped their conversation but didn’t seem to suspect anything. Or maybe they did? It was hard to tell if the longer clasp of hands for the greeting between Kuroo and Matsukawa, and then pulling the latter closer in a subtle way, wasn’t in some sense taking Matsukawa hostage, just making sure, that any possible (they couldn’t be sure a prank would occur, after all) prank would be, if not abandoned, then at least delayed. But, apparently, Hanamaki was willing to bear the sacrifice. 

A few seconds later, with the only warning being a happy, vibrant, but short melody of bells, reminiscent of the last notes of a music box, Oikawa and Kuroo’s cups—or rather the content of their cups—shot up like water from a fountain, drenching them both along with Matsukawa. 

“Hanamaki Takahiro,” the latter growled, pinning his laughing friend with a fierce gaze, “You traitor.”

Bokuto sprinted to the Slytherin table, trying to get to know the details of what happened with a goofy smile. 

The majority of students present in the Hall devoted their attention to this mess for literally around two and a half seconds before getting back to their dinners, used to the shenanigans of this part of the troublesome squad. Iwaizumi, on the other hand, approached his friends. With a skeptic tone of voice, he asked Hanamaki: “Was this what you were planning during History of Magic today?”

Hanamaki shook his head.

“Puh-lease. Does this look like something that requires so much preparation?”

“Makki!” Oikawa groaned, indignant. When he noticed Iwaizumi, he added, “Iwa-chan!”, like he expected his boyfriend to punish the culprit later, during quidditch training. Iwaizumi rolled his eyes at this. Oikawa pouted.

“That insult requires a blood spill, y’know,” Kuroo added.

“Bro, I’m on your side!” Bokuto exclaimed enthusiastically. 

“I appreciate the support, bro, but it’s something I must do alone.”

“You don’t want my help?”

“I would take his offer if I were you, you know,” Hanamaki quipped. “You’ll need it.”

“Hana—You asshole, what did you say? Are you questioning my competency?”

“Sleep with one eye open tonight, Makki, I’ll take my revenge!”

“Hey, Bokuto, if Kuroo doesn’t want your help, then I’ll take it.”

“Hey, hey, hey, Mattsun, do you want to be my new bro?”

“Sure, bro.”

“Bro.”

“Matsukawa, how dare you steal my best friend, my bro?” 

“You abandoned him first.”

“Matsukawa, Issei, are you trying to say that our friendship meant nothing to you? What about our bromance?” 

“Said the guy who betrayed me just a moment ago.”

“Nevermind all that. It means war!”

“Exactly!”

“I’m in!”

The chaos exploded quickly. Iwaizumi observed the scene for a few more seconds before turning on his heel.

“Idiots,” he muttered under his breath. He was heading back to the Gryffindor table when Akaashi stopped him. He and Kenma had watched the situation as if tired of their life, but also with some sort of (carefully masked) fondness.

“Iwaizumi, we have an offer for you.”

Iwaizumi looked at both Ravenclaws, then again at the chaos, which involved two of his friends, his boyfriend, Akaashi’s boyfriend and Kenma’s closest friend. He sat at the bench by the Ravenclaw table and leaned closer to his companions. He was pretty sure he already knew their proposition.

“I’m all ears.”

* * *

The war between the boys promised to be truly serious, and it indeed came true a few days later.

Nobody had it easy, though. They all knew quite a few secret entrances and exits in the walls of Hogwarts. Besides, they put to use their passions and talents. Kuroo, for example, who was the best seventh year regarding Potions and Herbology, had a wide range of possibilities.

The only one who could fully defend himself was probably Matsukawa, almost as good in the latter subject, but with an additional ace up his sleeve: being muggle-born. He had a lot of non-magic tricks at his disposal this way.

Oikawa and Hanamaki were a serious competition, too, as the former was the best student in Charms (and also in History of Magic and Astronomy, but that’s not important right now), and the latter excelled in Defense Against the Dark Arts and Divination. The Gryffindor had no guarantee that the second subject would come in handy, but he could always try, right?

Bokuto wasn’t to be disregarded either, of course. His talent, which let him collect Outstandings in his OWLs for the Care of Magical Creatures and Transfiguration, compensated for his rather poor grades in other subjects. Besides, as the rumors said, he had such a talent and was so good at the second one branch of magic, that he became an animagus with no problem! You could never know if the owl that just flew over your head was just an ordinary owl, or if it was Bokuto. The only one who knew the truth was probably Akaashi. And perhaps Kuroo, too, about whom there were similar rumors, but not so numerous and not supported by any irrefutable evidences. 

Either way, every one of them had something to brag about. Not to mention that each of them could splendidly fly on the broom, too. It was quite obvious—after all, they all played quidditch, and you’re not accepted to the team just for your looks.

* * *

After the first prank, Kenma sighed deeply, Akaashi rolled his eyes, barely stopping a tender smile from blooming on his face, and Iwaizumi decided that he should focus on studying for N.E.W.T.s, because if he spent his time in the library, he wouldn’t be exposed to this whole mess.

Namely—one morning, just after the breakfast, in this little break before the first lesson, Hanamaki was lured outside and there he was snatched up by a thestral to go on a little ride. By no means was this free ride in the usual carriages, though. And not on the ground, either. 

Hanamaki’s screaming betrayed his initial fear and surprise, as he held on for dear life to something his eyes couldn’t see, but the fear quickly turned into excitement. He liked the prank more than he should have, and Bokuto, although glad his friend liked the flight over the lake, had lost his good mood a little bit. It wasn’t what he was going for!

Akaashi reassured his boyfriend that the idea was a good one. Bokuto promised to try harder. The Ravenclaw smiled, told him he believed in him, and kissed him fleetingly on the cheek before heading down the corridor for Arithmancy, leaving Bokuto filled with new fervor.

* * *

The second prank left Kuroo glued to the ceiling in the corridor on the fourth floor for the whole second period. The sticking charm turned out to be so strong that the Slytherin couldn’t get rid of it on his own. He vowed to himself he wouldn’t treat Oikawa leniently anymore, despite belonging to the same house, and that he would catch him soon in their Common Room. 

Kenma marched under him indifferently, only sparing him a single amused glance. Akaashi ignored him completely, even though Kuroo was sure he noticed him. Iwaizumi wasn’t lucky enough to observe his friend’s adventure and his free internship as a new fresco, but Kuroo—or rather his robe—was sticking to him every few minutes during the Potions, confirming the rumors that had already spread all around Hogwarts. Iwaizumi understood quickly why Hanamaki switched places with him after entering the class, and Oikawa decided he liked Suga’s company better.

* * *

Despite his earlier promise to get his revenge on Oikawa first, Kuroo’s first victim was Matsukawa. The Slytherin had talked the paintings into helping him (it wasn’t that hard, what with his personal charm and manipulative skills) and lured the Hufflepuff into the Room of Requirement. It was now a pool apparently, and not just an ordinary pool—an Olympic size pool filled with hundreds of liters of green dye potion. It also occupied the floor of the whole room, not leaving even a centimeter of dry land. 

When Matsukawa crossed the chamber threshold (not suspecting that the perfectly smooth, shining floor was not, in fact, a floor) he fell with a big splash right into the trap. By the time he floated to the surface and, hanging onto the door threshold, or really, the only edge of the pool, and swiped his hair out of his forehead, so the potion dripping from it wouldn’t get into his eyes, he saw Kuroo right above him, grinning triumphantly. There was only one thing the Slytherin didn’t foresee: Matsukawa had really good reflexes. With a single yank, the Hufflepuff got his revenge. At least partially, since the dye from the potion didn’t leave a visible memento on the green robes of the Slytherin house like they did on yellow Hufflepuff ones, but at least the two of them both were forced to walk around with a skin colour deviating from the norm for the next couple of days.

* * *

Hanamaki had a quaint, though to be honest, a bit cruel, sense of humor that showed in the prank he pulled on Oikawa. Over the next few days he sent his friend devious glances and smiles that looked innocent enough, but, at the closer inspection, were purposely a little too wide, predatory even, and just a tad alarming. The Slytherin had ignored them at first, but indeed become more cautious and sensitive to even the quietest of sounds. 

After a few days, Oikawa’s suspiciousness reached the limits of the absurd. He chose the farthest place away from his friend during the joint lessons the Gryffindors and Slytherins had together, even though they used to sit close. Before going to sleep, he checked his mattress, blanket, pillow, the curtain, his coffer, Kuroo’s coffer, Sugawara’s coffer, and Semi’s coffer (even if Suga snorted with laughter and Semi rolled his eyes with irritation every time), and then the space under and behind his bed. It was only when he didn’t find anything that he let himself fall asleep with his wand in his hand. It was similar during every meal, too. Before Oikawa took something to his mouth, he waited until someone else tried the dish, as if he suspected Hanamaki of acquaintance with the Elves working in the kitchen and of a strength of persuasion big enough for him to pull them along in the prank preparations.

Iwaizumi couldn’t do anything about his boyfriend’s sudden paranoia, but they were spending a little bit more time together now, since Oikawa felt safe in his presence. The Slytherin complained about Hanamaki, then, and listed all the ideas for the revenge he could think of, trusting that Iwaizumi wouldn’t tell anything to their friend. Well, he was right, but he didn’t expect what was to come. 

But Oikawa wasn’t the only one disgruntled with the prank. 

“He did this deliberately,” Kuroo explained, irate, “He knew I wanted to take my revenge on Oikawa, so he made sure I won’t get a chance with him being all paranoid.”

Kenma only nodded, fully absorbed by the game he took from home, as usual. 

“And I had such a good plan, just listen...”

Kenma listened.

* * *

Matsukawa started to spend more time with Hanamaki again, just as if the whole prank war didn’t take place. He hadn’t approached him with a plan of negotiation and preliminary conditions of non-aggression pact. He just acted like the fight-not-really-a-fight from a few days ago didn’t happen at all.

At first, the Gryffindor was cautious. He inspected Matsukawa’s face, which was still greenish, with a careful look, wondered if the dyeing potion didn’t influence his memory by Kuroo’s error, or if his friend didn’t fell prey to someone else’s prank and it was the reason his memories were altered. Or something like this. Either way, Hanamaki didn’t intend on falling into paranoia like the one he caused to Oikawa. He treated Matsukawa in a friendly manner, but kept his distance, still not knowing what to expect nor what is waiting for him. 

After a week Hanamaki got a feeling that whatever he ate, the taste was always the same: cream puffs. 

“Why cream puffs?” Iwaizumi asked once, watching Matsukawa neatening the pouch with some herbs—which the Hufflepuff was secretly adding in bigger and bigger doses to Hanamaki’s meals for a few days now—so it wasn’t visible under his robe. Matsukawa shrugged. 

“If he likes them so much, then let him have it. Besides, he will have enough of them at some point and won’t mooch us for some time. Don’t you want to save some money?”

* * *

“I will buy you a Remembrall.”

“Iwa-chan, I don’t forget anything! My things disappear, it’s not the same, you know. It’s probably Makki’s fault… I’ll prank him so bad!”

Iwaizumi rolled his eyes. He was leaning on the door frame in Oikawa’s room and watched as his boyfriend loitered around the room, looking for the Transfiguration textbook. He couldn’t find it anywhere. 

“It won’t be a problem if you won’t have it. Come on.”

Oikawa sighed and followed Iwaizumi. 

The textbook wasn’t the only thing he lost this day. He couldn’t find his hair tie that was useful during quidditch trainings when his hair, a little too long, kept falling into his eyes thanks to the wind; nor his half-empty box of Bertie Bott's Every Flavour Beans; nor even his lucky pendant with the outstandingly ugly troll that looked like an alien and was a gift from Iwaizumi on their first date. 

Hanamaki promised he didn’t know anything about it, but the Slytherin didn’t believe him at all and declared with a solemn face and determination shining in his eyes that it’s time to take them all seriously. Iwaizumi felt chills running up his spine. 

The next morning during the breakfast, an eagle-owl landed on the Slytherins table. It left a package wrapped in a simple packing paper and sat next to Oikawa’s plate. The boy carefully unpacked it and found inside all the things he lost the day before. The owl hooted at him. 

“Yeah, yeah, help yourself,” he muttered. 

The eagle-owl took some grilled meat and flew away.

Oikawa followed it with his eyes till the bird flew through the open window and disappeared from the view. This owl looked awfully familiar… 

No one noticed Akaashi and Kenma exchanging meaningful glances.

* * *

Oikawa didn’t idle. The next day, wherever Matsukawa went, an armor followed him. It jingled metallic during the Potions; the wind howled gloomily inside it during the Care of Magical Creatures; on the meals it took away all the appetit thanks to its penetrating empty glare from its dark close helmet that Matsukawa could feel piercing the back of his head; it scared him in the night with its dark, still silhouette. During Astronomy it actually turned out to be pretty nice backrest, even if it was cold and hard; you could successfully hide cheat sheets in the gaps; and you could finally stop worrying your towel will get wet while taking a bath, you could just hang it on the armor! Besides, Matsukawa had a good excuse to postpone studying to the final exams for a few more days. He couldn’t take the armor with him to the library due to the noise it did, so he left it in front of the room once. Not long after, it started to bang on the doors, enough to blow its obstacle to pieces. 

This day Hanamaki, Iwaizumi, Oikawa and him have been asked to leave the library. 

Matsukawa was so moved he called the armor Hachiko.

* * *

The prank Kuroo has pulled on Bokuto required precision, discretion and, unfortunately, the help from the outside. The perfect candidate, like Slytherin thought, was Yukie, a Hufflepuff herself. During the next trip to Hogsmeade he gave the girl a neatly prepared package wrapped in a simple packing paper and tied with pretty, wide ribbon with little owls on it. It was even in the Hufflepuff colours! 

Kuroo observed from behind the corner like Yuki gives Bokuto the gift and only shrugs lazily at the question from who it is if not from her, and then like excited boy unties the beautiful bow… And like the package explodes in his face, hundreds of tiny paper owls flying away hooting, covering with light grey dust not only the Hufflepuff’s surprised face, but also his black hair put on a gel. Bokuto blinked owlishly, disoriented, trying to understand what exactly happened. He looked in the exhibition window next to which he was standing, and wiped his cheeks, forehead, nose and chin with the sleeve of his robe. Kuroo turned away to leave, satisfied with his prank, when he heard:

“Hey, Kuroo! Thanks, man! I look awesome, I’m leaving it like it is now!” 

The Slytherin looked over his shoulder at his friend. Bokuto was grinning happily, still dirty with the dust and thanks to this he looked like a small kid that had the best day of his life just a moment ago. 

Kuroo didn’t even care he was discovered, he just rolled his eyes and snorted with laughter.

* * *

The next few days were similar. Bokuto sneaked inside Kuroo’s room and covered every face on the books covers and photos with faces of Mike and Sully from the _Monsters, Inc._ (Oikawa, thanks to friendship with Matsukawa, was the only one in the Slytherins room beside Kuroo, who recognised the lovely faces from the movie); Hanamaki repaid Matsukawa with a prophecy according to which even knowledge of the prank wouldn’t save him from his Destiny (and in this way the Hufflepuff became a victim of the prank they both discussed during the History of Magic what felt like ages ago), but Hanamaki didn’t miss his own meeting with Destiny by large “d’, because thanks to Oikawa he woke up one morning in the middle of the lake, adrift on the huge leaf. It wasn’t his lucky day, by the way, since the same evening Kuroo added some potion to his bath and in the result some of the freckles on his nose started to glow and blink like Christmas tree lights. Even the successful prank he pulled on Bokuto didn’t fully improve his mood. It was a pretty creative prank, too. Thanks to this one spell, colorful ribbons fell from the Hufflepuff’s robe with every movement and followed him. Matsukawa, on the other hand, went full on and with the help of lucky coincidence, caught in his next prank not only Oikawa but Bokuto, too (the second one still was leaving a trail with the ribbons, then. He repaid him not long after, too). 

All five of them were so focused on their little war that they completely lost contact with what is going on around them. During the lessons they were planning the next pranks, in their free time—they observed their surroundings and tried to foresee every possible scenario, so they won’t fall into a trap. Once, even, after countless sleepless nights, Hanamaki passed out from exhaustion and dreamed that he successfully pulled a perfect prank on Oikawa (again. He had to take his revenge for the leaf prank, after all!). Later, the Gryffindor discovered with satisfaction, the vision came true! He wasn’t sure, though, if it was glimmer of precognition or if it was his brain trying to bribe him with little nice dreams to sleep more often and to not bring himself to this state with sleep deprivation again. 

Either way, they were forgetting about reality completely sometimes. Even Oikawa and Kuroo, usually extremely perceptive, had totally devoted their attention to the war. And this is probably why they didn’t expect the thing that was just about to come. 

During one of the breakfasts Bokuto got mysteriously and dangerously sounding strip of paper with beautifully written words: “You’re next.” He looked around the Hall, stopped to stare meaningfully at each and every one of his prank-rivals-slash-enemies-slash-friends, and in response, got only similar glances, as distrustful and paranoid as he felt right in this moment. 

And that’s when all hell broke loose. 

Mail owls flew into the Great Hall. Four of them, though, instead of packages or envelopes, held small pouches in their claws. They bombarded Oikawa, Matsukawa, Hanamaki and Kuroo with them. In one quick moment, the boys’ ears got longer and covered with grey fur, so they looked like donkey’s ears. Four surprised pairs of eyes scanned the Hall and noticed the three other friends were met with similar fate to them. They all turned to Bokuto. The Hufflepuff looked at the strip of paper he got before the breakfast, again, gulped and flew to the corridor like an arrow shot from the bow. The others followed him right away. 

“Bokuto!”

“It wasn’t me!” he screamed, only by sort some of miracle not crashing into the armor standing just behind the corner. 

“If it wasn’t you, then why the hell are you the only one with normal ears?”

“If it were me pulling a prank for all of you, I would sacrifice myself to not give you a reason to revenge! Nor cooperation!”

“So you telling us someone framed you?”

“Exactly!”

“Or maybe it was your plan all along? To save yourself and blame someone else at the same time with explanation like this?”

“Or maybe you are the one who did this, huh? You’re trying too hard to put the blame on me. And you’re threatening me with the letters!”

“What letters are you talking about?” 

Bokuto didn’t have time to explain, though, because the chase has cornered him in the dead end. However, before his friends could do anything, an owl flew from right around the corner, dropped a pouch on Bokuto’s head (his ears evolved into the donkey ones right away), then made a circle around all five of them, spilling something looking like a purple glitter, and flew away. Not only did the owl glide upward in the air, by the way, because suddenly all five of them floated up uncontrollably, inflated like balloons and stopping mid-air about fifteen meters above the ground of the first floor. 

“Okay, who planned this? You can tell me. I swear I want just congratulate the idea, I won’t take revenge,” Hanamaki promised, already coming up with a perfect plan for a revenge. 

He got showered with spite, excuses and accusations of stealing one’s ideas.

Three people, however, observed everything from their hiding spot. They exchanged amused smiles and high-fived.

“Did Yukie decide what does she want for borrowing her owl?” Iwaizumi asked. Akaashi shook his head. 

“She mentioned a video at first, so we’re shooting just in case,” he glanced at Kenma, who was filming everything with his phone, which was smuggled in a similar way as his game console. “If she decides she wants something more, I’ll let you know.”

“Okay, thanks. Now sorry guys, the quidditch match is the day after tomorrow, we have the last training today. I should go.”

“See you later.”

“Later,” Kenma muttered. 

The sounds of the quarrel could be heard in the staircase even when not long after Ravenclaws went to their Common Room.


End file.
